+
Lesson Plan
West Contra Costa Unified School District

Law of Sines

For Teachers 10th - 12th Standards
One must obey the sine laws. A lesson introduces and derives the Law of Sines for non-right triangles. With examples that use the Law of Sines to determine unknown measures in triangles, the lesson checks to see if the Law of Sines also...
+
Lesson Plan
Willow Tree

Angle Sum Property of Triangles

For Students 8th - 11th Standards
All triangles have some things in common. Using these properties of triangles, learners find missing angle measures. Scholars use the Angle Sum Property and properties of special triangles throughout the lesson.
+
Assessment
Mathematics Assessment Project

Circles in Triangles

For Students 9th - 12th Standards
Circles, and triangles, and tangents, oh my! In the assessment task, learners first answer questions leading to the radius of an inscribed circle for a given right triangle. They then use the result to independently determine the radius...
+
Workbook
1
1
Utah Education Network (UEN)

Geometric Figures and Scale Drawings

For Students 7th Standards
Scale up your lessons on geometry and ask learners to investigate conditions on triangles, scale drawings, the area and circumference of circles, and angle relationships. The resource includes activities and a homework assignment.
+
Handout
Del Mar College

Formulas for Elementary and Intermediate Algebra

For Students 6th - 9th Standards
Give your scholars the support they need to work with formulas. A reference page offers definitions and picture examples of perimeter, area, surface area, volume, the Pythagorean theorem, a variety of shapes, and more. 
+
Lesson Plan
EngageNY

Analytic Proofs of Theorems Previously Proved by Synthetic Means

For Students 9th - 12th Standards
Prove theorems through an analysis. Learners find the midpoint of each side of a triangle, draw the medians, and find the centroid. They then examine the location of the centroid on each median discovering there is a 1:2 relationship....
+
Worksheet
Mt. San Antonio Collage

Isosceles Triangles and Special Line Segments

For Students 9th - 12th Standards
Under which conditions can a triangle be classified as isosceles? High schoolers practice identifying isosceles triangles and special line segments, including angle bisectors, medians of triangles, and perpendicular bisectors of sides of...
+
Handout
Charleston School District

The Sum of Angles in a Triangle

For Students 8th Standards
An informative lesson contains a brief explanation of how the sum of the angles of a triangle is a line. The lesson continues with determining the missing angle in a triangle, or solving for a variable. Using the sum of the angles, the...
+
Handout
Charleston School District

Similar Triangles

For Students 8th Standards
Are they similar? The lesson provides an explanation of the angle-angle criterion for triangle similarity. Several problems allow the class to determine whether the two triangles with the given angle measures are similar or not. 
+
Handout
McGraw Hill

Triangles

For Students 4th - 7th Standards
After reviewing characteristics of seven types of triangles, young geometers discover how to find the missing angle of a triangle. Then, they practice identifying triangles, find missing angles, and find missing side lengths of similar...
+
Unit Plan
MENSA Education & Research Foundation

Shapes - Kindergarten

For Teachers K - 2nd Standards
Extend scholars' learning experience with a unit consisting of five shape lesson plans, an extension activity, assessment, and rubric. Begin by reading a story about shapes, then conduct an overview and assign pupils' their first...
+
Assessment
Los Angeles County Office of Education

Assessment for the California Mathematics Standards Grade 5

For Students 5th Standards
Test young mathematicians' knowledge with an assessment aligned to California's fifth grade state standards. The exam covers a multitude of concepts including fractions and decimals, positive and negative numbers, measurement; and how to...
+
Printables
1
1
Houghton Mifflin Harcourt

Unit 3 Math Vocabulary Cards (Grade 1)

For Students 1st Standards
Reinforce math vocabulary with a set of flashcards. Each card showcases a boldly typed word or a picture representation with labels. The topics are geometry related and include terms such as cones, faces, pyramids, sides, and more! 
+
Assessment
Los Angeles County Office of Education

Assessment for the California Mathematics Standards Grade 3

For Students 3rd Standards
Assess scholars' knowledge with a 22-page assessment that covers place value, patterns, probability, estimation, measurement, geometric figures; and their ability to add, subtract, multiply and divide proficiently. 
+
Lesson Plan
EngageNY

Special Lines in Triangles (part 2)

For Teachers 9th - 10th Standards
Medians, midsegments, altitudes, oh my! Pupils study the properties of the median of a triangle, initially examining a proof utilizing midsegments to determine the length ratio of a median. They then use the information to find missing...
+
Unit Plan
1
1
Houghton Mifflin Harcourt

Surprise!: English Language Development Lessons (Theme 2)

For Teachers 1st Standards
Surprise! is the theme of this series of ESL lessons. Cover an array of topics such as where we live, different times of day, shapes, the city and the country, what we do for fun, jobs, and games, all while practicing how to express...
+
Lesson Plan
Fayetteville Public Schools

I've Seen That Shape Before

For Teachers Pre-K - 2nd Standards
The objectives in the resource allow students to explore the characteristics of simple solid shapes. Youngsters learn to recognize the face shapes, corners, and edges that make up 3-D figures by filling in a chart. Lastly, learners look...
+
Activity
Early Childhood Education

Shape It Up!

For Teachers Pre-K - 1st Standards
The best way to understand shapes is to make them. Young geometers explore basic shapes through a variety of gross motor and fine motor activities. Shape sorting, singing songs about shapes, and eating shape snacks are just a few of the...
+
Lesson Plan
Learner

Solid Shapes

For Teachers K - 2nd Standards
A collection of two lessons, kindergartners will identify two-dimensional shapes in solid shapes. They will develop basic knowledge of the components that make up a sphere, rectangular prism, pyramid, cylinder, cone, and cube. Young...
+
Worksheet
2
2
American Farm Bureau Foundation for Agriculture

Shapes on the Farm

For Students K - 2nd Standards
Whether you live in the city, the suburbs, or out on the farm, shapes are everywhere in the world around us. Presented with an illustration of a farm, youngsters are tasked with coloring in all of the triangles, rectangles, squares, and...
+
Lesson Plan
1
1
Illustrative Mathematics

Equal Area Triangles on the Same Base II

For Teachers 9th - 12th Standards
A deceptively simple question setup leads to a number of attack methods and a surprisingly sophisticated solution set in this open-ended problem. Young geometers of different strengths can go about defining the solutions graphically,...
+
Lesson Plan
1
1
Illustrative Mathematics

Right Triangles Inscribed in Circles II

For Teachers 9th - 10th Standards
So many times the characteristics of triangles are presented as a vocabulary-type of lesson, but in this activity they are key to unraveling a proof. A unique attack on proving that an inscribed angle that subtends a diameter must be a...
+
Lesson Plan
1
1
Illustrative Mathematics

Right Triangles Inscribed in Circles I

For Teachers 9th - 10th Standards
One of the basic properties of inscribed angles gets a triangle proof treatment in a short but detailed exercise. Leading directions take the learner through identifying characteristics of a circle and how they relate to angles and...
+
Printables
1
1
K-5 Math Teaching Resources

2-D Shape Cards

For Students K - 5th Standards
Add some visual support to your elementary geometry lessons with this set of printable shape cards. From triangles and squares to octagons and nanogons, this simple resource can be used in countless ways to develop children's knowledge...